How frequently to paint the bottom, if at all?

[bsangs]

Saw a post about bottom paint on another forum - sorry for the wandering eye - and thought I'd ask a question here.

We keep our 35-3 in the water year-round. The bottom was last painted in 2020 or 2021 by the previous owner. Was planning to get it repainted next spring, but my diver seems to think that would be a waste of money, since he cleans it every month or so. What are the thoughts here about necessity and frequency of painting? I'm just a cruiser, no racing involved.

 

[Bolo]

I think it depends on where you keep the boat and the water conditions every season. I’m on the Chesapeake @ Annapolis and for some reason I’ve heard dock reports from other boat owners, both sail and motor, that they’ve have a lot of scum and growth on their hulls this past sailing season. (Global warming?) I have my bottom repainted every other year not only for that but to get a good look at the bottom, rudder, fittings, etc. I’ve never had a diver clean the bottom. It seems to have worked for me over the recent years. I also have prop speed applied he very other year which helps quite a bit and yes, it’s expensive but I think worth it because a few sailors I’ve talked to at my marina, who didn’t have prop speed, complained about a lot of growth that affected propulsion. The other factor, I think, is that we sail much more than most others on our dock as opposed to the occasional sailor which might be allowing hull growth. Its the “moving target is harder to hit” theory I guess.

 

[Pete the Cat]

Saw a post about bottom paint on another forum - sorry for the wandering eye - and thought I'd ask a question here.

We keep our 35-3 in the water year-round. The bottom was last painted in 2020 or 2021 by the previous owner. Was planning to get it repainted next spring, but my diver seems to think that would be a waste of money, since he cleans it every month or so. What are the thoughts here about necessity and frequency of painting? I'm just a cruiser, no racing involved.

I would probably go with your diver's recommendation. Buildup of paint is a problem on the East Coast and painting too often can be a problem--many yards just slather more paint without taking the time to sand. I haul my East Coast boat seasonally and do not paint it each year--painted every second or third year but it is in the water for only 5 months. My West Coast boat is in the water year round and I have a diver every 3 months and that has worked well since early 2021 with him reporting the paint in good condition last month. I don't race officially, but sail a lot and would be fussy about losing half a knot to growth, but the new paints (they differ in effectiveness but some are very very good) are ablatives and meant to last seasons with diver attention. If you have a good diver, good quality paint (ask the boatyard folks because different paints work differently in some areas), I do not see the problem with waiting. My California diver attends to the running gear and prop and it really does not look bad, even though the boat sits for months when I am in Maine, so I have not used prop speed. I used to paint more often but learned that it just does not make that much difference. With boatyard costs increasing rapidly, a good diver can save a lot of money, some provide videos which can be helpful.

 

[Christian Williams]

I've wondered. I have a diver monthly ($40 per), and repaint maybe 3-4 years. I often think that the diver is probably rubbing the paint off.

But when I had a skiff with gelcoat bottom, after only one week in the water here, barnacles started. Actual calcium. Had to use a scraper. Same is true, to lesser extent, to an inflatable left in the water.

Probably varies by area, but as little scrubbing as needed makes sense.

 

[Pete the Cat]

I've wondered. I have a diver monthly ($40 per), and repaint maybe 3-4 years. I often think that the diver is probably rubbing the paint off.

But when I had a skiff with gelcoat bottom, after only one week in the water here, barnacles started. Actual calcium. Had to use a scraper. Same is true, to lesser extent, to an inflatable left in the water.

Probably varies by area, but as little scrubbing as needed makes sense.

I think the professional divers (there is an association here in the SF Bay Area) have developed processes to clean without "rubbing" much of the paint off. And I am told some of the new ablatives are a bit harder than the old ones and made for repeated cleaning--without going to hard epoxy bottom paint. Here in the SF Bay cleaning is going to cost more like $3 to $4 a foot, but it is still worth it if a new bottom paint job (no place to DIY anymore here) is needed at $2400. I think you do not want to let hard growth started because scrubbing will then be needed, so I think may be such a thing as too much scrubbing, but I also think there could be too little if you are getting growth that is hard or adhesive.

 

[Loren Beach]

For one data point, here is the current verbiage from the web site for the yard that does our bottom painting. Rocky Pointe Marina and Boatyard. We repaint on a two to three year interval.
_______________
"Bottom Paint $30/ft* (min charge 25′ – $750) 2 Coats Paint – plus paint
Per foot rate includes round trip lift to and from water or trailer, blocking, pressure wash, standard preparation hand scuff and application of paint.

Paint cost is extra and sold 10% above our wholesale cost based on quantity used. We stock hard modified epoxy, durable ablative and soft ablative paints. Owners can provide their own paint if desired. "
________________
For our boat, the cost (without paint cost added) would be $1020. The cost goes up if additional sanding or grinding is needed...

As for hiring a diver to clean the slime off of our boat's bottom at the slip, an independent diver scrubs it for $100 to $120. Several times, from spring to fall, with a 3M pad. Cash.

 

[Frank Langer]

For one data point, here is the current verbiage from the web site for the yard that does our bottom painting. Rocky Pointe Marina and Boatyard. We repaint on a two to three year interval.
_______________
"Bottom Paint $30/ft* (min charge 25′ – $750) 2 Coats Paint – plus paint
Per foot rate includes round trip lift to and from water or trailer, blocking, pressure wash, standard preparation hand scuff and application of paint.

Paint cost is extra and sold 10% above our wholesale cost based on quantity used. We stock hard modified epoxy, durable ablative and soft ablative paints. Owners can provide their own paint if desired. "
________________
For our boat, the cost (without paint cost added) would be $1020. The cost goes up if additional sanding or grinding is needed...

As for hiring a diver to clean out boat's bottom at the slip, an independent diver scrubs it for about $120. Several times from spring to fall, with a 3M pad. Cash.

Wow, that would sure increase maintenance costs!
I haul our boat every two years, with haulout costing $340 $C for the four days required. Paint is $289, sometimes cheaper on sale. I do a light sand with 80 grit, apply two coats of paint myself. While it's drying I disassemble and grease my folding prop, lubricate the thru hulls, wax the hull topsides, replace zincs, and then I'm ready to relaunch. Total cost is about $700 $C, about $500 US.
I dive down at least once a month in the summer, less in winter, to clean the hull--good exercise for me, at no extra cost.
I'm glad I live on the BC coast.
Frank

 

[Loren Beach]

I am glad to hear that you are saving money. That said, there might be some California owners envious of both of us!

 

[Christian Williams]

80F today.